A team of researchers from UC Santa Barbaras’s Marine Science Institute and the Bren School of Environmental Science found some surprising results after they affixed satellite tracking tags on 15 grey reef sharks off the coast of the Republic of the Marshall Islands.
Of those 15 tagged sharks, eight of them were likely poached by illegal fisherman in the roughly 2 million square kilometers of which has been declared a safe haven for sharks. The initial study intended to survey the sharks’ movement in the protected waters around the Marshall Islands’ Exclusive Economic Zone. Instead the tracking data showed the sharks ended up in places as far as ports in Guam and the Philippines.
“It’s not the study we expected,” researcher Darcy Bradley said. “Instead, we uncovered a high level of illegal shark fishing from within the Marshall Islands shark sanctuary.”
Based on the number of tagged sharks that were caught and removed from the sanctuary, the researchers, who presented their findings in the most recent issue of Conservation Letters, estimated that even a healthy population of sharks “would collapse to less than 10 percent of its unfished state in fewer than five years.”
The unexpected findings suggest that despite the sanctuary designation, the risk of being caught was not enough to deter illegal shark fishing operations and that active monitoring and enforcement need to be part of the system. The answer could be more tracking devices in the area. Not for the sharks, however, but for the boats. The researchers suggest that requiring satellite tracking devices any fishing vessel entering the sanctuary would help enable real-time monitoring of the sizable sanctuary.
“The ability to ‘see’ all boats in all places in near real-time using satellite tracking technology would provide a means to monitor for compliance with multiple fisheries management goals—be they combatting illegal fishing, monitoring transshipments, identifying fishing activity in high bycatch areas and more,” Bradley said.
The researchers also recommend partnerships between international groups, stakeholder nations, nonprofit and private sector entities, and local-level participants to find consensus, adopt strategies and advance policies that would result in more effective shark sanctuaries.
“For the shark sanctuary model to work, we need to think creatively about ways to closely monitor all fishing activities within sanctuary borders,” Bradley said. “Currently, we have the technology to make this happen, we just lack the buy-in.”